Homopolymers of THF and of alkylene oxides, and copolymers of THF and alkylene oxides, are known and can be used as soft segment glycols in the preparation of polyurethanes. Processes disclosed in the art for producing such polymers, like that shown in British Pat. No. 845,958, also produce OCE byproducts, which may constitute as much as 7-15%, by weight, of a polymerizate.
The presence of these oligomeric cyclic ethers in a polymerizate can be undesirable for several reasons. First, the ethers are nonfunctional impurities and can represent an economic penalty to a purchaser of a polymerizate because up to 7-15%, by weight, of the material purchased contains no reactive hydroxyl groups and may therefore be useless for the purposes intended. Secondly, when such a polymerizate is used in preparing a polyurethane, the ethers tend to degrade the polyurethane's properties. This degradation manifests itself in much the same way as that encountered when an excess of plasticizer is used: the lower molecular weight oligomeric cyclic ethers vaporize slowly at elevated temperatures and are leached out by water and common organic liquids, which results in weight loss and undesirable dimensional changes in the polyurethane product.
A need therefore exists for a simple, inexpensive method for reducing the OCE content of a THF-, an AO-, or a THF/AO polymerizate. This need is filled by the process of the invention, whereby the OCE content of such a polymerizate is reduced by bringing it into contact with a particular type of hydrocarbon.